import pygame
from pygame.sprite import Sprite


class Ship(Sprite):
    """管理飞船的类"""

    def __init__(self, ai_game):
        """初始化飞船并设置其初始位置"""

        super().__init__()
        # 将self添加screen屏幕
        self.screen = ai_game.screen
        # 给self添加属性setting
        self.settings = ai_game.settings
        # get_rect()访问屏幕的rect属性
        self.screen_rect = ai_game.screen.get_rect()

        # 加载飞船图像并获取其外接矩形
        self.image = pygame.image.load('../images/ship.png')
        self.rect = self.image.get_rect()

        # 在屏幕底部中心启动
        # self.rect.midbottom = self.screen_rect.midbottom
        # 在屏幕左侧中心启动
        self.rect.midleft = self.screen_rect.midleft

        # 在飞船的属性x（水平坐标轴）中存储小数值
        # self.x = float(self.rect.x)
        # 在飞船的属性y（垂直坐标轴）中存储小数值
        self.y = float(self.rect.y)
        # 移动标志
        # self.moving_right = False
        # self.moving_left = False
        self.moving_up = False
        self.moving_down = False

    def update(self):
        """根据移动标志调整飞船的位置"""

        # 更新飞船的x值，而不是rect对象。
        # if self.moving_right and self.rect.right < self.screen_rect.right:
        #     self.x += self.settings.ship_speed
        # if self.moving_left and self.rect.left > 0:
        #     self.x -= self.settings.ship_speed
        # 更新飞船的y值，而不是rect对象。
        if self.moving_down and self.rect.bottom < self.screen_rect.bottom:
            self.y += self.settings.ship_speed
        if self.moving_up and self.rect.top > 0:
            self.y -= self.settings.ship_speed

        # 根据self.x更新rect对象
        # self.rect.x = self.x
        # 根据self.y更新rect对象
        self.rect.y = self.y

    def blitme(self):
        """在指定位置绘制飞船."""
        self.screen.blit(self.image, self.rect)

    def center_ship(self):
        """让飞船在屏幕左侧居中"""
        # self.rect.midbottom = self.screen_rect.midbottom
        # self.x = float(self.rect.x)
        self.rect.midleft = self.screen_rect.midleft
        self.y = float(self.rect.y)